首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   2125438篇
  免费   153566篇
  国内免费   6582篇
耳鼻咽喉   28433篇
儿科学   63462篇
妇产科学   55894篇
基础医学   307204篇
口腔科学   60902篇
临床医学   198351篇
内科学   409923篇
皮肤病学   42833篇
神经病学   171718篇
特种医学   79531篇
外国民族医学   445篇
外科学   315051篇
综合类   47324篇
现状与发展   6篇
一般理论   684篇
预防医学   165604篇
眼科学   47715篇
药学   160739篇
  28篇
中国医学   5973篇
肿瘤学   123766篇
  2021年   16508篇
  2019年   16967篇
  2018年   23932篇
  2017年   18368篇
  2016年   20050篇
  2015年   23035篇
  2014年   31412篇
  2013年   47146篇
  2012年   64821篇
  2011年   68350篇
  2010年   40014篇
  2009年   37193篇
  2008年   63655篇
  2007年   66941篇
  2006年   67756篇
  2005年   65339篇
  2004年   62287篇
  2003年   59415篇
  2002年   57707篇
  2001年   104962篇
  2000年   108391篇
  1999年   90807篇
  1998年   23810篇
  1997年   21354篇
  1996年   21119篇
  1995年   19919篇
  1994年   18528篇
  1993年   17197篇
  1992年   70699篇
  1991年   68620篇
  1990年   66454篇
  1989年   63891篇
  1988年   58812篇
  1987年   57257篇
  1986年   54111篇
  1985年   51740篇
  1984年   38047篇
  1983年   32298篇
  1982年   18229篇
  1979年   34267篇
  1978年   23716篇
  1977年   19823篇
  1976年   18528篇
  1975年   19543篇
  1974年   23862篇
  1973年   22928篇
  1972年   21474篇
  1971年   20204篇
  1970年   18947篇
  1969年   17520篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
91.
AIM: The intention was to investigate cerebrospinal fluid pressure (CSFP) and volume of cerebrospinal fluid (CSF) drained during and after thoracic- and thoracoabdominal aneurysm repair. The findings were related to the occurrence of postoperative neurologic deficits. METHODS: Twenty-nine patients (12 with thoracic and 17 with thoracoabdominal aortic aneurysm) were operated without shunting or extracorporeal circulation. For monitoring of CSFP an intrathecal catheter was placed in all patients. The volume of CSF withdrawn intraoperatively, on the day of operation as well as on the 1st and 2nd postoperative day was recorded. RESULTS: Twenty-six patients had no postoperative neurologic sequelae. One patient had postoperative paraplegia while 2 had paraparesis. The three patients with neurologic sequelae had higher CSFP intraoperatively than those without neurologic symptoms (P=0.04). Median CSFP during aortic cross-clamping was 19 mmHg and 10 mmHg and the median volumes of CSF drained on the day of operation 210 and 85 mL in the two groups, respectively. There was a significant positive correlation between CSFP and central venous pressure. CONCLUSIONS: A higher intraoperative CSFP was observed in patients with neurologic sequelae following thoracic- and thoracoabdominal aneurysm repair. Further, there was a tendency of higher volumes of CSF drained in this group of patients. Although, the series is too small to allow firm conclusions, it supports the view that CSFP monitoring and drainage is beneficial during thoracic- and thoracoabdominal aneurysm repair.  相似文献   
92.
93.
BACKGROUND: Stressful conditions lead to formation of excessive free radicals, and lipid peroxidation is one of the major outcomes of free radical-mediated injury that directly damages membranes and generates a number of secondary products. OBJECTIVES: To determine the levels of malondialdehyde, an end product of lipid peroxidation, according to demographic and occupational variables in workers of a prehospital emergency service and to analyse the relationship between malondialdehyde levels and burnout. MATERIAL AND METHODS: One hundred and eleven healthy workers of a prehospital emergency service and eighty aged-matched healthy individuals of both sexes as a control group were surveyed. Malondialdehyde levels were measured by the Bull and Marnett method. To measure burnout, the Maslach Burnout Inventory was used. RESULTS: Professional category is associated with lipid peroxidation and burnout levels (Malondialdehyde levels were: physicians 338.10+/-14.47, nurses 329.17+/-12.62 and technicians 296.74+/-14.28; burnout levels were: physicians 41.29+/-3.59, nurses 37.38+/-6.05 and technicians 35.33+/-5.87). Working at night and in the evening increased malondialdehyde and burnout levels. Malondialdehyde levels increase with age. No significant variations with respect to sex were detected. Significant variations in malondialdehyde levels were detected between singles (303.13+/-12.74) and married people (344.43+/-13.43) but not with respect to divorcees (326.44+/-11.74). Significant differences were detected in erythrocyte malondialdehyde levels between smokers (341.37+/-17.09) and nonsmokers (302.21+/-12.38), but not for alcohol consumption. CONCLUSIONS: These findings suggest a positive correlation between malondialdehyde, a biomarker of lipid peroxidation and occupational stress, as estimated by elements of the Maslach Burnout Inventory, and oxidative stress.  相似文献   
94.
95.
96.
97.
98.
Primary chemotherapy administered to breast cancer patientsis the best model to identify baseline features able to predictwhich patients may be most likely to benefit or not from a cytotoxicregimen. In the March issue of Annals of Oncology two papersevaluated the predictive role of immunohistochemical p53 expressionon  相似文献   
99.
100.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号